Starwheels have been used in continuous processing lines for a number of years to properly orient articles such as bottles, cans and other containers beneath filling heads, before labelling machinery, beneath capping devices and the like. Continuous processing lines are often used with various articles to maximize use of the capital investment in the line and to increase productivity. Due to the variety of sizes and shapes of articles to be passed through such lines, one type of starwheel does not generally accommodate a great number of article configurations. Typically, a starwheel has an outer peripheral surface which is contoured to substantially match the outer periphery of a particular article to be run through the line. Therefore, it has been necessary to keep a number of starwheels on hand. A certain amount of time is required to substitute starwheels when a new size or shape of article is to be run through the line.
To avoid these disadvantages, U.S. Pat. No. 4,378,665 to Crankshaw et al. teach the use of a starwheel having a resilient outer peripheral surface which accommodates containers of various sizes and shapes by flexing when the container is squeezed between the starwheel and a guide. This puts pressure against the container and it may rub against the guide during the time it is in contact with the starwheel. This starwheel also lacks a means by which containers can be accurately spaced around the periphery of the starwheel.
In U.S. Pat. No. 2,713,960, Siegal shows a starwheel that employs a stretched spring to accommodate variations in contour of the articles to be passed through a continuous line. Like the Crankshaw et al. starwheel, the spring can undesirably press the container between the guide and the starwheel spring. Since the container can move against the spring, it is possible that the container could become misoriented (e.g., due to friction against the guide) as it travels around the line while in contact with the starwheel.
U.S. Pat. No. 4,124,112 to Mohney et al. teaches an odd-shaped container indexing starwheel which uses hemispherical clamps to grasp the outer periphery of an article and thus accommodate articles of various sizes and shapes. This requires a rather complex system of mechanical parts to cause the clamps to properly close around an article.
U.S. Pat. No. 1,365,773 to Dickerson uses a fixed peripheral surface starwheel in combination with flattened S-shaped springs on the outside perimeter of the line to guide and move the articles into individual pockets on the starwheel to properly position them for filling.
To further show the state of the art, U.S. Pat. Nos. 1,708,313 to Larsen and 2,176,557 to Lippold employ starwheels which have fixed surfaces for receiving articles.
U.S. Pat. No. 2,184,493 to Gladfelter uses a fixed starwheel surface which is fed by a large wheel containing individual bottle holders. Guide brackets 57 are secured to a stationary table so that they can be moved inwardly or outwardly according to the diameter of the bottles in the line. FIG. 12 shows a bottle cap latch which has a coil spring 119 which pulls the two cap latches 116 together.
U.S. Pat. No. 4,355,669 to Miller teaches an apparatus for canning food having components 24 and 26 which can be varied to fit any size food container.
In a different field of art, devices consisting of a plurality of movable wires held in a locking brace are sometimes used in carpentry to obtain the contour of a corner or other odd-shaped surface. The device is pressed against the corner and the rods move in to obtain a contour of the corner which can then be transferred to a piece of wood which is shaped to fit the corner.